Processing a copy command directed to a first storage architecture for data that is stored in a second storage architecture

ABSTRACT

Provided are a computer program product, system, and method for processing a copy command indicating a source set comprising a subset of source logical addresses to copy to an indicated target set comprising a subset of target logical addresses. Complete is expected to be returned to the copy command in response to completing the copying of the source set to the target set. A point-in-time (PiT) copy establish command is generated in response to receiving the copy command, indicating the source and target sets in the copy command, The generated PiT copy command is executed to generate copy information indicating the source and target sets of source logical addresses and whether they have been copied to the target set. Complete is returned to the copy command after generating the copy information and before copying all the source logical addresses to the target logical addresses.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a computer program product, system, andmethod for processing a copy command directed to a first storagearchitecture for data that is stored in a second storage architecture.

2. Description of the Related Art

Hosts in a data storage environment may submit data to a storagecontroller 2 that manages access to one or more storage devices. Hostsmay be configured to use a set of data management commands for a FixedBlock Address (FBA) format, where data is expressed in fixed sizeLogical Block Addresses (LBAs). One such data management command is theSCSI extended copy (XCOPY) command that specifies a range of sourcelogical addresses to copy to target logical addresses in one or morelogical volumes.

There is a need in the art for improved techniques for a storagecontroller to implement a copy command from a host expressing the sourceand target data as logical addresses.

SUMMARY

Provided are a computer program product, system, and method forprocessing a copy command directed to a first storage architecture fordata that is stored in a second storage architecture. The copy commandindicates a source set comprising a subset of source logical addressesin at least one storage to copy to an indicated target set comprising asubset of target logical addresses in the at least one storage. Completeis expected to be returned to the copy command in response to completingthe copying of the source set to the target set. A point-in-time (PiT)copy establish command in response to receiving the copy command. ThePiT copy establish command indicates the source and target sets in thecopy command, wherein the source logical addresses map to source tracksin the source device and wherein the target logical addresses map totarget tracks. The generated PiT copy command is executed and inresponse to executing the PiT copy establish command, copy informationis generated indicating the source set of source logical addresses andthe target set of target logical addresses and indicating whether thesource logical addresses in the source set have been copied to thetarget set. Complete is returned to the copy command after generatingthe copy information and before copying all the source logical addressesto the target logical addresses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of a computing environment.

FIG. 2 illustrates an embodiment of a Point-in-Time (PiT) copy establishcommand to establish a PiT copy relationship.

FIG. 3 illustrates an embodiment of source/target relationshipinformation.

FIG. 4 illustrates an embodiment of a copy map for the PiT copyrelationship.

FIGS. 5 a and 5 b illustrate an embodiment of operations to establish aPiT copy relationship.

FIG. 6 illustrates an embodiment of operations to process an update to asource logical address in a PiT copy relationship.

FIG. 7 illustrates an embodiment of operations to perform a backgroundcopy operations for a PiT copy relationship.

FIG. 8 illustrates an embodiment of a copy command as known in the priorart.

FIG. 9 illustrates an embodiment of operations to process a copy commandform a host.

DETAILED DESCRIPTION

Described embodiments provide techniques for processing a copy commandfrom a host that is intended for a data storage architecture that isdifferent from the data storage architecture in which the data to copyis stored. For instance, the copy command may be expressed in FBAs,whereas the controller processing the command may store the data in atrack architecture. In the described embodiments, the controllergenerates a PiT copy establish command for the source and target logicaladdresses specified in the copy command and executes the PiT copyestablish command to establish the PiT copy relationship information andinitiate a background copy operation to copy the data in the PiT copyrelationship. Complete may be returned to the host after establishingthe PiT copy relationship and before all the data is copied.

FIG. 1 illustrates an embodiment of a computing environment having acontroller 2 to copy data from a coupled source storage 4 a having oneor more logical volumes 6 a to a coupled target storage 4 b having oneor more volumes 6 b. The controller 2 includes a processor 8 and memory10. Hosts (not shown) may direct read and write requests to the firstcontroller 6 a to access tracks in the first storage 4 a and the secondstorage 4 b. A host write to a track in the first storage 4 a in apoint-in-time (“PiT”) copy relationship 16 may result in the replicationof that track to the second storage 4 b. In a further embodiment, thetarget storage 4 b may be coupled to a target controller, so that thecontroller 2 would communicate the PiT data being copied to the targetcontroller to manage the copying to the target storage 4 b. Thecontroller 2 may communicate with the storages 4 a, 4 b over a network10.

The memory 10 includes a copy manager 12 to copy data from the sourcestorage 4 a to the target storage 4 b as specified in one or more PiTcopy relationships 14. A copy relationship 14 may identify sourcelogical addresses in a source volume 6 a to copy to target logicaladdresses in a target volume 6 b. Alternatively, both the source andtarget logical addresses in the PiT copy relationship 14 may be in asame volume in one of the storages 4 a, 4 b. The data to copy in thecopy relationship 14 may be part of a consistency session or consistencygroup, such that data is copied in a manner to maintain consistencyacross all dependent data, so that the order of dependent writes ispreserved to make the data consistent as of a point-in-time.

The PiT copy relationship 14 includes source relationship information 20and target relationship information 22 both providing information on thesource and target tracks involved in the copy operation. Thisinformation is used to manage I/O requests to the source and targetvolumes to determine if the I/O requests are to tracks involved in a PiTcopy operation. The PiT copy relationship 14 further includes a copy map24 indicating tracks in the target volume 6 b to which source logicaladdresses in the source set need to be copied.

The copy manager 12 may implement a PiT program such as IBM FlashCopy®,snapshot, and other PiT programs, to perform a PiT copy operationbetween specified source and target logical addresses in the same ordifferent volumes. or volume. (FlashCopy is a registered trademark ofInternational Business Machines, Corp. or “IBM”). The PiT copy operationmay be between a source set of source logical addresses comprising asubset of the logical addresses in a source volume 6 a and a target setof target logical addresses comprising a subset of the logical addressesin a target volume 6 b. The logical addresses may comprise logical blockaddresses (LBAs) that map to contiguous tracks in the volumes 6 a, 6 b.

The copy manager 12 is shown in FIG. 1 as program code loaded into thememory 10 and executed by the processor 8. Alternatively, some or all ofthe functions of the copy manager 12 may be implemented in hardwaredevices in the controllers 6 a, 6 b, such as in Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGA), etc.The controller 2 may include other programs not shown, such as anoperating system and application programs.

The memory 10 may comprise one or more volatile or non-volatile storagedevices, such as a Dynamic Random Access Memory (DRAM), Random AccessMemory (RAM) or a non-volatile memory, e.g., battery backed-up RandomAccess Memory (RAM), static RAM (SRAM), solid state storage devices(SSDs), etc.

The storages 4 a, 4 b may each comprise one or more storage devicesknown in the art, such as interconnected storage devices, where thestorage devices may comprise hard disk drives, solid state storagedevice (SSD) comprised of solid state electronics, such as a EEPROM(Electrically Erasable Programmable Read-Only Memory), flash memory,flash disk, Random Access Memory (RAM) drive, storage-class memory(SCM), etc., magnetic storage disk, optical disk, tape, etc. Thestorages 4 a and 4 b may store tracks in a Redundant Array ofIndependent Disks (RAID) configuration where strides of tracks arewritten across multiple storage devices comprising the storages 4 a, 4b. ranks

The network 10 may comprise a network such as a Local Area Network(LAN), Storage Area Network (SAN), Wide Area Network (WAN), peer-to-peernetwork, wireless network, etc.

FIG. 2 illustrates an embodiment of a PiT copy establish command 50 thatis submitted within the controller 2 or from an attached host to causethe copy manager 12 to generate a PiT copy relationship 14. The PiT copyestablish command 50 includes a command field 52 specifying the PiT copyestablish command; a first source logical address 54 to be copied; alast source logical address 56 to be copied; a first target logicaladdress 58 to which the first source logical address 54 is copied; and alast target logical 60 to which the last source logical address 56 iscopied; and other parameters 62, such as a background copy parameterindicating whether a background operation is performed to copy thesource logical address to the target logical addresses and indicatingwhether the source logical addresses should remain persistent afterbeing copied. The command 50 further would indicate the source volume 6a including the source logical addresses and the target volume 6 bincluding the target logical addresses in the PiT copy relationship 14being established. Additional information may further be indicated, suchas the source 6 a and target 6 b volumes or single volume 6 a, 6 b inwhich the copy operation is being performed. The source and targetlogical addresses may be stored in data storage devices other thanlogical volumes. From the range of first 54 and last 56 source logicaladdresses, the number of logical addresses to copy may be determined.

When processing the PiT copy establish command 50, the copy manager 14generates data structures and information for the PiT copy relationship14 as shown in FIGS. 3 and 4.

FIG. 3 shows fields 70 included in the source 20 and target 22relationship information, which includes a PiT copy identifier (ID) 72identifying the PiT copy for the information; a first source logicaladdress 74 including the first source logical address 54 to copy; afirst target logical address 76 to which the first source logicaladdress 74 is copied; a length related to a number of the logicaladdresses to copy 78, such as in the field 58; and the other parameters80, such as included in the field 60. The number of logical addresses tocopy 78 may alternatively be expressed in other storage units, such asthe number of target tracks or extents to copy. The source and targetrelationship information 70 would further indicate the source volume 6 aincluding the source logical addresses and the target volume 6 bincluding the target logical addresses in the relationship 14. Thesource and target relationship information 70 may be used to manageaccess to the source 6 a and target 6 b volumes, respectively, while thePiT copy relationship 14 is active.

FIG. 4 illustrates and embodiment of a copy map 24, which may comprise abitmap that includes a cell for each track in the target volume 6 b, ortarget location, including the target set of logical addresses. Thecells for the target tracks including the target set of target logicaladdress to receive source logical addresses are set to indicate copy,e.g., “1”. The cells representing tracks in the target volume 6 b thatare not part of the PiT copy relationship, i.e., excluding the targettracks including the target set, may have a value to indicate that theyare not to be copied, e.g., “0”. Other values and settings could be usedto indicate the tracks to copy and the tracks not to copy as part of thePiT copy relationship being established. Thus, each cell set to indicateto copy represents a plurality of target logical addresses involved inthe copy operation.

The cells, indicators, in the copy map 24 may each represent a targetgroup of target logical addresses, including target logical addresses ininvolved in the copy relationship tracks 14. The target groupsrepresented by the indicators, cells, in the copy map 14 may eachrepresent groupings of logical addresses other than tracks. In a furtherembodiment, the copy map 24 may indicate tracks in the source volume 6 ahaving the source set of logical addresses to copy.

FIGS. 3, 4, and 5 provide an embodiment of information included in thePiT copy establish command, the source and target relationshipinformation, and the copy map. This information described as included inthese data structures and commands is not considered to be limiting, andadditional and modified information may be included in differentembodiments. Further, the information described in FIGS. 3, 4, and 5 maybe separated into additional commands and data structures.

FIGS. 5 a and 5 b illustrate an embodiment of operations performed bythe copy manager 12 to process a PiT copy establish command 50 toestablish a PiT copy relationship 14, such as a FlashCopy establishcommand, e.g., FCESTABL. With respect to FIG. 5 a, the copy manager 12receives (at block 100) a PiT Copy Establish Command 50 indicating thefirst 54 and last 56 source logical addresses and the first 58 and last60 target logical addresses. The copy manager 12 determines (at block102) a first source track including the first source logical address 54and a first target track including the first target logical address 56to which the data is copied. The copy manager 12 would use a volume mapto determine the mapping of logical addresses to tracks in the storages4 a, 4 b. The copy manager 12 quiesces (at block 104) Input/Output (I/O)operations to the source set of logical addresses to copy. The copymanager 12 then generates (at block 106) source relationship information20 indicating the first source track 74, the first target track 76, andthe length 78 related to the logical block addresses to copy. The copymanager 12 further quiesces (at block 108) I/O operations to the targetset of logical addresses to be updated. The copy manager 12 generates(at block 110) target relationship information 24 indicating the firstsource logical address 74, the first target logical address 76, and anumber of logical addresses to copy 78. In the quiesce operations atblock 104 and 108, the copy manager 12 may quiesce I/O to only thedetermined source set and target set of logical addresses to copy or totracks including the source and target sets of logical addresses.Alternatively, the quiesce of I/O may be to the entire volumes 6 a, 6 b.

The copy manager 12 generates (at block 112) a copy map 24 includingindicators, e.g., cells, wherein each indicator represents a pluralityof logical block addresses, such as a track. The copy manager 12determines (at block 114) copy indicators comprising indicators in thecopy map 24 representing the tracks including the target set of targetlogical addresses. With respect to FIG. 5 b, the copy manager 12determines (at block 120) whether only a portion of the first targettrack or the last target track, in the range of tracks including thetarget set, includes target logical addresses in the target set. If not,which means the source logical addresses to copy line up and fill eachtrack including the target set of logical addresses, then the copymanager 12 sets (at block 122) all the copy indicators to indicate thatthe source logical addresses mapping to the target tracks represented bythe copy indicators need to be copied.

If (from the yes branch of block 120) only a portion of the first orlast target track includes logical addresses in the target set, then thecopy manager 12 copies the data for those target tracks that onlypartially include target set logical addresses as part of establishingthe PiT copy relationship 14. The copy map 24 will not indicate to copythe first or last target tracks updated as part of the establishcommand. In this way writes to a portion of the target track that didnot include the logical addresses in the target set will not be copiedas part of the PiT relationship because they copy map 24 will notindicate that the target tracks partially including PiT data need to becopied. If (at block 126) only a portion of the first target trackincludes logical addresses in the target set, then the copy manager 12copies (at block 128) the source logical addresses that map to the firsttarget track to the first target track. If (at block 130) only a portionof the last target track includes logical addresses in the target set orif (from the no branch of block 126) the first target track does notonly partially store logical addresses of the target set, then the copymanager 12 copies (at block 132) the source logical address in thesource set that map to the last target track to the last target track.

After copying logical addresses for the first and/or last target track(from block 132 or the no branch of block 130), the copy manager 12 sets(at block 134) the copy indicators, except for the first target trackand/or the last target track that are updated, to indicate that thesource logical addresses for the target tracks represented by the copyindicators needs to be copied, e.g., to one. The copy indicators for thefirst and/or last target track that are updated at blocks 128 and/or 132are not set to indicate that the source tracks need to be copied. Aftergenerating the PiT relationship information and data structure (fromblock 122 or 130), such as the copy map 24 and after copying sourcelogical addresses in the source set that map to partial filled firstand/or last target tracks (from block 134), complete is returned (atblock 138) to the application or user that initiated the PiT copyestablish command 50.

In an alternative embodiment where the copy map 24 indicates sourcetracks having the source set of logical addresses, if the source set ofsource logical addresses maps to only a portion of a first source trackand/or a last source track including a portion of the source set oflogical addresses, then the first source track and/or the last sourcetrack only partially filled with PiT logical addresses are copied to atleast one of the corresponding target tracks as part of the PiTestablish relationship operation. In such case, the copy map 24 wouldnot indicate that the first and/or last source tracks need to be copied.Further, in this alternative embodiment, the returning of the completeto the virtual copy establish command is performed in response tocopying the first source track and/or the last source track to thecorresponding target tracks.

After the PiT copy relationship 14 is established, hosts (not shown) maysubmit writes to the controller 2 for source logical addresses in thesource volume 6 a including data in one of the established PiT copyrelationships 14. The writing of data to a source logical address in aPiT copy relationship 14 that has not been copied to the target volume 6b would trigger the copy manager 12 to perform a copy-on-write operationto copy data at the source logical addresses in the copy relationship 14to the target storage 6 b before they are updated so as to preserve thePiT relationship.

In certain described embodiments, upon receiving a write to a sourcelogical address in a copy relationship 14, the copy manager 12determines a target group of target logical addresses also in the copyrelationship, such as a target track, that include the source logicaladdress to update. The copy manager 12 determines the source logicaladdresses corresponding to the target logical addresses in the targetgroup, and copies the determined source logical addresses to thedetermined target group. In this way, the mapping of the source andtarget logical addresses in the relationship information 70 is used todetermine the source logical addresses in the copy relationship 14 thatneed to be copied to the target storage 6 b. This type of mapping isperformed because in certain described embodiments the source logicaladdresses in the source set are in source tracks that may be differentnumbered tracks than the target tracks including the target set oflogical addresses to be updated by the source logical addresses in thedestage group.

FIG. 6 illustrates an embodiment of operations performed by the copymanager 12 to process an update to a source logical address in a sourcevolume 6 a. If a write request is directed to multiple source logicaladdresses, then the operations of FIG. 6 may be performed for eachsource logical address in the write. Upon receiving (at block 200) theupdate, the copy manager 12 considers the source relationshipinformation 20 to determine (at block 202) whether the source logicaladdress to update is within the range of source logical addresses, asdefined by the first source logical address 74 and the number logicaladdresses 78 (FIG. 3), in one PiT copy relationship 14. If not, the copymanager 12 copies (at block 204) the update to the source volume 6 a. If(at block 202) the source logical address to update is in one PiT copyrelationship 14, then the copy manager 12 determines (at block 206) thetarget track including the target logical address in the target set tobe updated by the source logical address being updated. This may bedetermined from the target relationship information 22 by determiningthe target logical address corresponding to the source logical addressto update from the ranges of source logical addresses and target logicaladdresses as defined by the first source logical address 74, the secondtarget logical address 76 and the number logical addresses to copy 78.

The copy manager 12 then determines (at block 208) whether they copy map24 for the PiT copy relationship 14 being considered indicates that thedetermined target, e.g., target group, track was updated, i.e., whetherthe bit or indicator for the determined target track, or target group,indicates the target track was updated. The indicator may indicate thetrack was updated if it does not indicate the track needs to be updatedor if it has a value indicating the track is current. If (from the yesbranch of block 208) the determined target track to which the sourcelogical address to update is to be copied has been updated, then the PiTdata for the source logical address has already been copied to thedetermined target track (target group) and control proceeds to block 204to write the update to the source logical address in the source volume 6a.

If (at block 208) the copy map 24 indicates the determined target trackhas not been updated, then the copy manager 12 determines (at block 210)the target logical addresses in the determined target track having thetarget logical address to update. The copy manager 12 determines (atblock 212) the source logical addresses in the source set to be copiedto the target logical addresses in the at least one target track. Thedetermined source logical addresses are then copied (at block 214) tothe determined target logical addresses in the target track or targetgroup. The at least one copy indicator in the copy map 24 for theupdated target track is set (at block 216) to indicate that the at leastone target track was updated. After the target track is updated, controlproceeds to block 204 to apply the update to the source logical address.

With the described embodiments of FIG. 6, an update to source logicaladdresses is processed by determining the source track including thesource logical addresses that will be destaged together. The targettracks having the source logical addresses to be destaged together isthen determined, and then source logical addresses are copied tocorresponding target logical addresses in the copy relationship as partof performing a copy-on-write for the updated source track.

Once the copying of the source logical addresses to the at least onetarget track is confirmed, the source track having the source logicaladdress to update is destaged to the source track, so that thepoint-in-time data is destaged and not overwritten with newer data.

FIG. 7 illustrates an embodiment of operations performed by the copymanager 12 to copy source logical addresses to target logical addressesin the copy relationship as part of a background copy operation if theestablish command 50 indicates a background copy operation 62. Thebackground copy operation is performed to copy all the source logicaladdresses in the PiT copy relationship 14 to the target volume 6 b toprovide a redundant copy of the source logical addresses. Uponinitiating (at block 250) the background copy operation, the copymanager 12 selects (at block 252) one indicator, e.g., bit, in the copymap 24 representing target logical addresses, e.g., a track, that havenot been updated. The copy manager 12 may select a bit in the copy map24 that that is adjacent in the copy map 24 to the last selected bit toupdate sequential target tracks. in the target volume 6 b. The copymanager 12 determines (at block 254) source logical addresses from thesource set that are to be copied to the selected target logicaladdresses. This may be determined from the source relationshipinformation 20 from the source and target logical address ranges definedin the source relationship information 20, by determining the sourcelogical addresses in the source range that correspond to the selectedtarget logical addresses.

The determined source logical addresses are copied (at block 256) to theselected target track and then the selected indicator in the copy map 24is set (at block 258) to indicate that the target track has beenupdated.

The described embodiments provide techniques for allowing a PiT copyestablish operation to specify source and target logical addresses thatmap to source and target tracks having the specified source and targetlogical block addresses, respectively. In described embodiments, a firstand/or last of the source tracks including the source logical addressesmay only have a portion of the source logical addresses to copy and afirst and last of the target tracks including the target logicaladdresses may only have a portion of the target logical addresses. Insuch case, the source logical addresses that map to only a portion ofthe first and/or last target tracks are copied to the first and/or lasttarget tracks during the establish operation. Further, the copy mapindicating target tracks that need to be updated with source tracks doesnot indicate that data needs to be copied for the first and/or lasttarget tracks for which the source logical addresses are copied duringthe establish operation.

The described embodiments further provide techniques for handlingupdates to source logical addresses in a PiT copy relationship. Becausesource tracks are destaged in a destage group, such as a track,including the updated source logical address, the described embodimentsdetermine the target tracks having the target logical addresses in thePiT copy relationship that are updated by source logical addresses inthe source track being destaged. The source logical addresses are thencopied to the corresponding target logical addresses in the determinedat least one target track in the PiT copy relationship.

Described embodiments further provide techniques for performing abackground copy operation of source logical addresses in a PiT copyrelationship by determining a copy indicator representing a targettrack, determining the source logical addresses that map to the targetlogical addresses in the target track in the PiT copy relationship, andthen copying the determined source logical addresses to the targettrack. The described embodiments allow the managing of updates andbackground copy operations for source logical addresses in a PiT copyrelationship when source and target data are expressed as logicaladdresses and when different ranges of source and target logicaladdresses are specified.

Host systems (not shown) connected to the controller 2 may submit a copycommand to the storage controller in a data storage format,architecture, that is different from the storage format, architecture,of the volumes 6 a, 6 b in the storages 4 a, 4 b. In one embodiment, thecopy command may be intended for a Fixed Block Address (FBA) storagearchitecture where the data to be copied is stored in storages 4 a, 4 bimplementing a track based data storage architecture, such as Count KeyData (CKD), where data records can be variable in length and where thetracks are expressed as a cylinder and head (CCHH) track location in thevolume.

In one of many possible implementations, the copy command may comprise aSmall Computer System Interface (SCSI) extended copy command (XCOPY) tocopy a range of source logical addresses, source set, from a sourcelogical volume to a range of target logical addresses, target set, in atarget volume. This command is intended not to complete until all thesource data is physically copied to the target data.

The described embodiments provide techniques for using a PiT copyestablish command to implement the copy command from the host. Thisallows a host that operates in an open volume environment, e.g., FBA, tosubmit commands that are implemented in a track based disk storageenvironment.

FIG. 8 illustrates an embodiment of a copy command 270 as known in theprior art intended for an FBA storage environment. The copy command 270may be implemented as the SCSI extended copy (XCOPY) command. The copycommand 270 includes an extended copy command 272 code identifying thecommand; a first source logical address in the source set of sourcelogical addresses to copy; a source logical unit 276 identifying thevolume or logical device including the source set to copy; a firsttarget logical address 278 in the target set of target logical addressto which the source logical addresses are copied; a target logical unit280 identifying the volume or logical device including the target set oftarget logical addresses to be updated; and a transfer length 282indicating a number of logical addresses to copy.

FIG. 9 illustrates an embodiment of operations performed by the copymanager 12 to process a copy command from a host (not shown) that isintended for a storage architecture, such as FBA, different from thestorage architecture of the volumes 6 a, 6 b in which the data isstored, e.g., track architecture. At block 300, the copy manager 12receives the copy command 270 indicating a source set comprising asubset of source logical addresses in at least one storage, e.g., thefirst target logical address 274 and transfer length 282 in the sourcelogical unit 276, to copy to an indicated target set in the at least onestorage comprising a subset of target logical addresses, e.g., the firsttarget logical address 128 and transfer length 282 in the target logicalunit 276. In response to this copy command for an FBA architecture, thecopy manager 12 generates (at block 302) a point-in-time (PiT) copyestablish 50 command indicating the source and target sets from thereceived copy command 270 and a background copy operation in field 52.

The copy manager 12 executes (at block 304) the generated PiT copyestablish command 50 and may perform the operations described withrespect to FIGS. 5 a and 5 b to generate the necessary PiT copyrelationship 14 information, including source 20 and target 22relationship information and a copy map 24. The copy manager 12generates (at block 306) copy information indicating the source set ofsource logical addresses and the target set of target logical addresses,such as the source relationship information 20 and the targetrelationship information 22. The copy manager 12 further generates (atblock 308) a copy map 24 including a plurality of indicators, such asbits in a bitmap. Each of the indicators represents a plurality of thetarget logical addresses, such as a target track, and include copyindicators representing tracks of target logical addresses in the targetset that have not been updated with the corresponding source logicaladdresses since the copy relationship 14 was established.

After generating the necessary data structures and copying sourcelogical addresses in only a partial target track according to FIGS. 5 aand 5 b, a complete is returned (at block 310) to the PiT copy establishcommand 50. In response to receiving the complete of the PiT copyestablish command 50, the copy manager 12 returns (at block 312)complete to the copy command 270 and initiates (at block 314) thebackground copy operation indicated in the PiT copy establish command50, such as described with respect to FIG. 7. In certain embodiments,the complete is returned to the copy command 270 before executing thebackground copy operation (at block 314).

In certain embodiments, the source tracks including the source set inthe source storage 6 a may be different numbered tracks than the targettracks including the target set of logical addresses. Further, thesource tracks and the target tracks including the source and target setsmay be in the same or different volumes.

With the described embodiments, the copy command from the host may befor a different data storage architecture than that the controller 2uses to store data in the volumes 6 a, 6 b and the copy command may besynchronous, requiring complete to be returned only after all thephysical data is copied. The copy manager 12 implements the copy commandin a PiT copy establish command intended for a different data storageenvironment. Complete is returned immediately to the host before all thedata is copied and after the necessary PiT copy relationship informationis created so that the data is copied asynchronously. In this way asynchronous copy command directed to a FBA storage architecture isconverted to an asynchronous copy operation in a track basedarchitecture.

The described operations may be implemented as a method, apparatus orcomputer program product using standard programming and/or engineeringtechniques to produce software, firmware, hardware, or any combinationthereof. Accordingly, aspects of the embodiments may take the form of anentirely hardware embodiment, an entirely software embodiment (includingfirmware, resident software, micro-code, etc.) or an embodimentcombining software and hardware aspects that may all generally bereferred to herein as a “circuit,” “module” or “system.” Furthermore,aspects of the embodiments may take the form of a computer programproduct embodied in one or more computer readable medium(s) havingcomputer readable program code embodied thereon.

Any combination of one or more computer readable medium(s) may beutilized. The computer readable medium may be a computer readable signalmedium or a computer readable storage medium. A computer readablestorage medium may be, for example, but not limited to, an electronic,magnetic, optical, electromagnetic, infrared, or semiconductor system,apparatus, or device, or any suitable combination of the foregoing. Morespecific examples (a non-exhaustive list) of the computer readablestorage medium would include the following: an electrical connectionhaving one or more wires, a portable computer diskette, a hard disk, arandom access memory (RAM), a read-only memory (ROM), an erasableprogrammable read-only memory (EPROM or Flash memory), an optical fiber,a portable compact disc read-only memory (CD-ROM), an optical storagedevice, a magnetic storage device, or any suitable combination of theforegoing. In the context of this document, a computer readable storagemedium may be any tangible medium that can contain or store a programfor use by or in connection with an instruction execution system,apparatus, or device.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electro-magnetic, optical, or any suitable combination thereof. Acomputer readable signal medium may be any computer readable medium thatis not a computer readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmittedusing any appropriate medium, including but not limited to wireless,wireline, optical fiber cable, RF, etc., or any suitable combination ofthe foregoing.

Computer program code for carrying out operations for aspects of thepresent invention may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Smalltalk, C++ or the like and conventional proceduralprogramming languages, such as the “C” programming language or similarprogramming languages. The program code may execute entirely on theuser's computer, partly on the user's computer, as a stand-alonesoftware package, partly on the user's computer and partly on a remotecomputer or entirely on the remote computer or server. In the latterscenario, the remote computer may be connected to the user's computerthrough any type of network, including a local area network (LAN) or awide area network (WAN), or the connection may be made to an externalcomputer (for example, through the Internet using an Internet ServiceProvider).

Aspects of the present invention are described above with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems) and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer program instructions. These computer program instructions maybe provided to a processor of a general purpose computer, specialpurpose computer, or other programmable data processing apparatus toproduce a machine, such that the instructions, which execute via theprocessor of the computer or other programmable data processingapparatus, create means for implementing the functions/acts specified inthe flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computerreadable medium that can direct a computer, other programmable dataprocessing apparatus, or other devices to function in a particularmanner, such that the instructions stored in the computer readablemedium produce an article of manufacture including instructions whichimplement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer,other programmable data processing apparatus, or other devices to causea series of operational steps to be performed on the computer, otherprogrammable apparatus or other devices to produce a computerimplemented process such that the instructions which execute on thecomputer or other programmable apparatus provide processes forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

The terms “an embodiment”, “embodiment”, “embodiments”, “theembodiment”, “the embodiments”, “one or more embodiments”, “someembodiments”, and “one embodiment” mean “one or more (but not all)embodiments of the present invention(s)” unless expressly specifiedotherwise.

The terms “including”, “comprising”, “having” and variations thereofmean “including but not limited to”, unless expressly specifiedotherwise.

The enumerated listing of items does not imply that any or all of theitems are mutually exclusive, unless expressly specified otherwise.

The terms “a”, “an” and “the” mean “one or more”, unless expresslyspecified otherwise.

Devices that are in communication with each other need not be incontinuous communication with each other, unless expressly specifiedotherwise. In addition, devices that are in communication with eachother may communicate directly or indirectly through one or moreintermediaries.

A description of an embodiment with several components in communicationwith each other does not imply that all such components are required. Onthe contrary a variety of optional components are described toillustrate the wide variety of possible embodiments of the presentinvention.

Further, although process steps, method steps, algorithms or the likemay be described in a sequential order, such processes, methods andalgorithms may be configured to work in alternate orders. In otherwords, any sequence or order of steps that may be described does notnecessarily indicate a requirement that the steps be performed in thatorder. The steps of processes described herein may be performed in anyorder practical. Further, some steps may be performed simultaneously.

When a single device or article is described herein, it will be readilyapparent that more than one device/article (whether or not theycooperate) may be used in place of a single device/article. Similarly,where more than one device or article is described herein (whether ornot they cooperate), it will be readily apparent that a singledevice/article may be used in place of the more than one device orarticle or a different number of devices/articles may be used instead ofthe shown number of devices or programs. The functionality and/or thefeatures of a device may be alternatively embodied by one or more otherdevices which are not explicitly described as having suchfunctionality/features. Thus, other embodiments of the present inventionneed not include the device itself.

The illustrated operations of the figures show certain events occurringin a certain order. In alternative embodiments, certain operations maybe performed in a different order, modified or removed. Moreover, stepsmay be added to the above described logic and still conform to thedescribed embodiments. Further, operations described herein may occursequentially or certain operations may be processed in parallel. Yetfurther, operations may be performed by a single processing unit or bydistributed processing units.

The foregoing description of various embodiments of the invention hasbeen presented for the purposes of illustration and description. It isnot intended to be exhaustive or to limit the invention to the preciseform disclosed. Many modifications and variations are possible in lightof the above teaching. It is intended that the scope of the invention belimited not by this detailed description, but rather by the claimsappended hereto. The above specification, examples and data provide acomplete description of the manufacture and use of the composition ofthe invention. Since many embodiments of the invention can be madewithout departing from the spirit and scope of the invention, theinvention resides in the claims herein after appended.

What is claimed is:
 1. A computer program product for processing a copycommand involving at least one storage, wherein the computer programproduct comprising a non-transitory computer readable storage mediumhaving computer readable program code embodied therein that executes tocause operations, the operations comprising: receiving a copy commandindicating a source set comprising a subset of source logical addressesin the at least one storage to copy to an indicated target setcomprising a subset of target logical addresses in the at least onestorage, wherein complete is expected to be returned to the copy commandin response to completing the copying of the source set to the targetset; generating a point-in-time (PiT) copy establish command in responseto receiving the copy command, wherein the PiT copy establish commandindicates the source and target sets in the copy command, wherein thesource logical addresses map to source tracks in the source device andwherein the target logical addresses map to target tracks; executing thegenerated PiT copy command; generating, in response to executing the PiTcopy establish command, copy information indicating the source set ofsource logical addresses and the target set of target logical addressesand indicating whether the source logical addresses in the source sethave been copied to the target set; and returning complete to the copycommand after generating the copy information and before copying all thesource logical addresses to the target logical addresses.
 2. Thecomputer program product of claim 1, wherein the copy command isdirected to data stored in a first data storage architecture and whereinthe PiT copy establish command is used for data stored in a second datastorage architecture different form the first data storage architecture.3. The computer program product of claim 2, wherein the first datastorage architecture comprises a Fixed Block Address (FBA) architectureand wherein the second data storage architecture comprises a trackstorage architecture where data is stored in track locations in volumes.4. The computer program product of claim 3, wherein the copy commandcomprises a SCSI extended copy command.
 5. The computer program productof claim 1, wherein the operations further comprise: receiving completeto the PiT copy establish command after generating the copy informationand before copying all the source logical addresses to the targetlogical addresses, wherein the returning of the complete to the copycommand is performed in response to receiving the complete to the PiTcopy establish command.
 6. The computer program product of claim 1,wherein the source tracks including the source set are differentnumbered tracks than the target tracks including the target set oflogical addresses.
 7. The computer program product of claim 1, whereinlogical addresses comprises logical block addresses (LBAs) and whereinthe source tracks and the target tracks are in a same volume or indifferent volumes in the at least one storage.
 8. The computer programproduct of claim 1, wherein the generated PiT copy establish commandindicates a background copy operation to cause the copying of the sourceset of logical addresses to the target set of logical addresses that areindicated as having not been copied.
 9. The computer program product ofclaim 8, wherein the operations further comprise: executing thebackground copy operation to copy the source set to the target set byselecting a source track including source logical addresses in thesource set to copy to a corresponding target track including targetlogical addresses in the target until the source set has been copied tothe target set.
 10. The computer program product of claim 9, wherein thecomplete is returned to the copy command before executing the backgroundcopy operation.
 11. A system in communication with at least one storage,comprising: a processor; and a computer readable storage mediumincluding computer program code executed by the processor to performoperations, the operations comprising: receiving a copy commandindicating a source set comprising a subset of source logical addressesin the at least one storage to copy to an indicated target setcomprising a subset of target logical addresses in the at least onestorage, wherein complete is expected to be returned to the copy commandin response to completing the copying of the source set to the targetset; generating a point-in-time (PiT) copy establish command in responseto receiving the copy command, wherein the PiT copy establish commandindicates the source and target sets in the copy command, wherein thesource logical addresses map to source tracks in the source device andwherein the target logical addresses map to target tracks; executing thegenerated PiT copy command; generating, in response to executing the PiTcopy establish command, copy information indicating the source set ofsource logical addresses and the target set of target logical addressesand indicating whether the source logical addresses in the source sethave been copied to the target set; and returning complete to the copycommand after generating the copy information and before copying all thesource logical addresses to the target logical addresses.
 12. The systemof claim 11, wherein the copy command is directed to data stored in afirst data storage architecture and wherein the PiT copy establishcommand is used for data stored in a second data storage architecturedifferent form the first data storage architecture.
 13. The system ofclaim 12, wherein the first data storage architecture comprises a FixedBlock Address (FBA) architecture and wherein the second data storagearchitecture comprises a track storage architecture where data is storedin track locations in volumes.
 14. The system of claim 13, wherein thecopy command comprises a SCSI extended copy command.
 15. The system ofclaim 11, wherein the operations further comprise: receiving complete tothe PiT copy establish command after generating the copy information andbefore copying all the source logical addresses to the target logicaladdresses, wherein the returning of the complete to the copy command isperformed in response to receiving the complete to the PiT copyestablish command.
 16. The system of claim 11, wherein the generated PiTcopy establish command indicates a background copy operation to causethe copying of the source set of logical addresses to the target set oflogical addresses that are indicated as having not been copied.
 17. Thesystem of claim 16, wherein the operations further comprise: executingthe background copy operation to copy the source set to the target setby selecting a source track including source logical addresses in thesource set to copy to a corresponding target track including targetlogical addresses in the target until the source set has been copied tothe target set.
 18. The system of claim 17, wherein the complete isreturned to the copy command before executing the background copyoperation.
 19. The system of claim 11, wherein the source tracksincluding the source set are different numbered tracks than the targettracks including the target set of logical addresses.
 20. The system ofclaim 11, wherein logical addresses comprises logical block addresses(LBAs) and wherein the source tracks and the target tracks are in a samevolume or in different volumes in the at least one storage.